JP4870722B2 - Vibration isolator - Google Patents

Description

  The present invention relates to a vibration isolator.

  Conventionally, for example, as a suspension support used in an automobile suspension mechanism, an inner cylinder member to which a piston rod of a shock absorber is inserted and fixed, and an annular rubber-like elastic body provided on an outer peripheral portion of the inner cylinder member, An anti-vibration device comprising: an outer member that is fixed to the vehicle body and has a cylindrical portion that accommodates the rubber-like elastic body, and is coupled to the inner cylinder member via the rubber-like elastic body. An apparatus is known (see, for example, Patent Document 1 below).

  In this type of vibration isolator, the outer member includes the upper first outer metal fitting and the lower second outer metal fitting that hold the rubber-like elastic body in the vertical direction, and the first outer metal fitting to hold the bound stopper. In some cases, the second outer metal fitting is fixed to the lower surface of the outer metal fitting. In that case, the first outer metal fitting and the second outer metal fitting are fixed by welding in a state where the outer peripheral flange portions overlap each other.

On the other hand, as a means for fixing the third outer metal fitting to the second outer metal fitting, there is a case where the opening edge of the third outer metal fitting is caulked and fastened to the opening of the second outer metal fitting. The coupling strength of the third outer metal fitting may be insufficient. For this reason, it is conceivable that welding is also performed for fixing the second outer metal fitting and the third outer metal fitting, but due to the relationship between the welding locations of the first outer metal fitting and the second outer metal fitting, the outer member as a whole has sufficient strength. Therefore, it is not easy to set the welding location of the second outer metal fitting and the third outer metal fitting.
JP 2003-278822 A JP-A-6-213264

  The present invention has been made in view of the above points, and includes an outer member having excellent strength by welding the three metal parts constituting the outer member of the vibration isolator with sufficient strength. An object is to provide a vibration isolator.

  The vibration isolator according to the present invention includes an inner cylindrical member, an annular rubber-like elastic body provided on an outer peripheral portion of the inner cylinder member, and a cylindrical portion that houses the rubber-like elastic body. And an outer member coupled to the cylindrical member via the rubber-like elastic body. The outer member includes a first outer metal fitting, a second outer metal fitting, and a third outer metal fitting, and the first outer metal fitting is a ring plate-shaped first abutting against one axial surface of the rubber-like elastic body. In addition to having a wall portion, the first flange portion is provided to extend outward in the direction perpendicular to the axis over the entire circumference. The second outer metal fitting has a ring-plate-like second wall portion that clamps the rubber-like elastic body in the axial direction between the first wall portion and is overlapped and fixed to the first flange portion. A second flange portion. Further, the third outer metal fitting is an annular metal fitting that is overlapped and fixed on the surface opposite to the first outer metal fitting with respect to the second wall portion of the second outer metal fitting. And in the overlapping part of the first flange part and the second flange part, bolt fastening parts with respect to the mounting surface are provided at two locations facing in the direction perpendicular to the axis across the axis of the inner cylinder member. ing. Here, the first flange portion of the first outer metal fitting and the second flange portion of the second outer metal fitting are arranged at six points equally arranged in the circumferential direction on the inner side perpendicular to the axis of the bolt fastening portion. The two outer welded portions fixed at the outer welded portion and opposed to each other in the direction perpendicular to the axis thereof are arranged on a straight line orthogonal to a straight line connecting the two bolt fastening portions. Further, the second wall portion of the second outer metal fitting and the third outer metal fitting are fixed at three inner welding portions arranged uniformly in the circumferential direction on the inner peripheral side of the outer welding portion, The one inner welded portion is arranged on a straight line orthogonal to a straight line connecting the two bolt fastening portions.

  According to the present invention, the first outer metal fitting and the second outer metal fitting are fixed by the outer welded portion at six points on the circumference, and the two outer welded portions thereof are not on the straight line connecting the bolt fastening portions. And the second outer metal fitting and the third outer metal fitting are fixed by three inner welded portions that are equally arranged in the circumferential direction so as to overlap the outer welded portion. The bonding strength of the members can be remarkably increased.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a plan view of a vibration isolator 10 according to one embodiment of the present invention, FIG. 2 is a longitudinal sectional view thereof, and FIG. 3 is a longitudinal sectional view in an assembled state to a vehicle body.

  The vibration isolator 10 is a suspension support for elastically coupling a piston rod 1 of a shock absorber in an automobile suspension mechanism to a vehicle body 2, and is made of metal into which an upper end portion of the piston rod 1 is inserted and fixed. An inner cylinder member 12, a metal outer member 14 surrounding the outer periphery of the inner cylinder member 12 and attached to the vehicle body 2, and a rubber-like elastic body interposed between the inner cylinder member 12 and the outer member 14. 16 and is provided with the axial direction X of the piston rod 1 as the vertical direction.

  The inner cylinder member 12 includes a cylindrical inner cylinder portion 18 and an inner cylinder flange 20 that projects from the upper end portion of the inner cylinder portion 18 to the outer side Y1 in the direction perpendicular to the axis Y. The upper end portion of the piston rod 1 is the inner end portion. It is fixed to the piston rod 1 by being inserted into the cylindrical portion 18 from below and tightening the nut 3.

  The rubber-like elastic body 16 is integrally vulcanized at the upper and lower sides so as to cover the inner cylinder flange 20 at the outer peripheral portion of the inner cylinder member 12, and is formed in an annular shape as a whole.

  The outer member 14 has a cylindrical portion 22 </ b> B that accommodates the rubber-like elastic body 16, and is coupled to the inner cylinder member 12 via the rubber-like elastic body 16. Specifically, the outer member 14 is composed of three metal fittings, a first outer metal fitting 22, a second outer metal fitting 24, and a third outer metal fitting 26 in order from the top.

  The first outer metal fitting 22 has a first wall portion 22A that is in contact with the upper surface 16A, which is one axial surface of the rubber-like elastic body 16, and a rubber-like shape extending downward from the outer peripheral edge of the first wall portion 22A. The cylindrical portion 22B that surrounds the rubber-like elastic body 16 in contact with the outer peripheral surface of the elastic body 16, and the entire circumference extending from the lower end of the cylindrical portion 22B toward the outer side Y1 in the direction perpendicular to the axis. A first flange portion 22C having a rhombus shape in plan view, and forms a cup shape with an open bottom. The first wall portion 22A has a ring plate shape and includes a circular opening 28 at the center.

  The second outer metal fitting 24 is in contact with the lower surface 16B, which is the other axial surface of the rubber-like elastic body 16, and holds the rubber-like elastic body 16 in the axial direction X with the first wall portion 22A. A wall portion 24A, and a second flange portion 24B extending from the second wall portion 24A toward the axially perpendicular direction Y1 over the entire circumference and fixed to the first flange portion 22C. In this example, as a whole, a flat plate shape is formed in a rhombus shape in plan view. The second wall portion 24A has a ring plate shape and includes a circular opening 30 at the center. An accommodation space for the rubber-like elastic body 16 is provided between the first outer metal fitting 22 and the second outer metal fitting 24. In addition, the standing wall part 24C is extended in the outer peripheral edge of the 2nd flange part 24B over the perimeter.

  The third outer metal fitting 26 is an annular metal fitting fixed to the second wall 24 </ b> A of the second outer metal fitting 24 so as to be overlaid on the lower surface 24 </ b> A <b> 1 that is the surface opposite to the first outer metal fitting 22. is there. The third outer metal fitting 26 is a holding member for holding a bounce stopper (not shown), a third wall portion 26A superimposed on the lower surface 24A1 of the second wall portion 24A, and a third wall portion 26A for holding the bounce stopper. It consists of a holding cylinder portion 26B extending downward from the outer peripheral edge of the three wall portions 26A. The third wall portion 26A includes a circular opening 32 at the center, and a caulking cylinder portion 32A extends upwardly from the opening 32, and the second metal fitting 24 is formed by the caulking cylinder portion 32A. It is fixed to the opening 30 by caulking.

  Circular bolt holes 34 and 36 serving as bolt fastening portions for the mounting surface 2A of the vehicle body 2 are provided in the overlapping portion of the first flange portion 22C and the second flange portion 24B so as to overlap each other. As shown in FIG. 1, the bolt holes 34 and 36 are provided at two locations facing the axis-perpendicular direction Y across the axis O of the inner cylinder member 12. Specifically, the first outer metal fitting 22 and the second outer metal fitting 24 have a rhombus shape in plan view with the axis O of the inner cylinder member 12 as the center, and the longer one of the two diagonal lines of the rhombus The bolt holes 34 and 36 are provided on the diagonal L, and the bolt holes 34 and 36 are provided at equal distances from the shaft core O on both sides of the shaft core O. In addition, the bolt 4 is press-fitted into the bolt holes 34 and 36 from below, and the outer member 14 is attached and fixed to the vehicle body 2 by fastening the bolt 4 to the mounting surface 2A.

  In the above basic configuration, in the present embodiment, the first outer metal fitting 22 and the second outer metal fitting 24 are fixed by welding, and the second outer metal fitting 24 and the third outer metal fitting 26 are fixed by welding. .

  Specifically, the first flange portion 22C of the first outer metal fitting 22 and the second flange portion 24B of the second outer metal fitting 24 are fixed by six outer welding portions 38 that are equally arranged in the circumferential direction C. Yes. As shown in FIG. 1, the outer welded portion 38 is equidistant (ie, at six locations on the circumference that surrounds the shaft core O concentrically on the inner side Y2 in the direction perpendicular to the axis from the bolt holes 34, 36). (60 ° intervals). Further, of the six outer welded portions 38, two outer welded portions 38A, 38A orthogonal to the axis-perpendicular direction Y connect the two bolt holes 34, 36 (that is, the longer diagonal line). It is set so as to be located on a straight line M (that is, the shorter diagonal line of the rhombus) perpendicular to L.

  In addition, the second wall portion 24A of the second outer metal fitting 24 and the third wall portion 26A of the third outer metal fitting 26 are three points on the inner circumference side of the outer welded portion 38, which are equally arranged in the circumferential direction C. It is fixed at the weld 40. The inner welded portion 40 is provided at equal intervals (that is, at an interval of 120 °) at three positions on the circumference surrounding the shaft core O in a concentric manner, and the inner welded portion 40 is circumferential with respect to the outer welded portion 38 on the outer peripheral side. One of the three inner welds 40 is positioned on a straight line M orthogonal to the straight line L connecting the two bolt holes 34 and 36 so that the positions in the direction C coincide with each other. It is set to be. Therefore, the inner welded portion 40 has an angle of 90 ° with the straight line L on two sides forming an angle of 30 ° with respect to the straight line L connecting the two bolt holes 34 and 36 and on the opposite side across the straight line L. Is set to one place.

  When manufacturing the vibration isolator 10, as shown in FIG. 6, the caulking cylinder portion 32A of the third outer metal fitting 26 is inserted into the opening 30 of the second outer metal fitting 24 from below, as shown in FIG. 5, the caulking tube portion 32 </ b> A is bent outward and is caulked and fastened, and the second wall portion 24 and the third wall portion 26 </ b> A are welded and fixed by the inner welded portion 40. In this example, the welding method is projection welding. Projection welding is a welding method in which projections (protrusions) are provided at the welding locations, current is concentrated and flowed through the protuberances, and heating and press-bonding are performed simultaneously. As shown in FIG. The second wall portion 24 is provided with a downward protruding portion 42, and the protruding portion 42 is crushed and welded by welding as shown in FIG.

  After the second outer metal fitting 24 and the third outer metal fitting 26 are welded in this manner, the inner cylinder member 12 with the rubber-like elastic body 16 that has been pre-cured and molded is accommodated in the cylindrical portion 22B. As shown in FIGS. 1 and 2, the first flange portion 22 </ b> C of the first outer metal fitting 22 and the second flange portion 24 </ b> B of the second outer metal fitting 24 are overlapped, and both are welded and fixed by the outer welded portion 38. Welding in this case is also performed by projection welding. In this example, as shown in FIGS. 4 and 5, the second flange portion 24B is provided with an upward protruding portion 44, and as shown in FIG. 2, the protruding portion 44 is formed by welding. Is crushed and welded.

  With the outer member 14 configured as described above, the strength of the outer member 14 with respect to the input in the axial direction X of the inner cylindrical member 12 is increased by the above-described specific arrangement configuration of the outer welded portion 38 and the inner welded portion 40. Can be significantly higher. In particular, by setting the inner welded portion 40 to the above three points on the circumference, the flow of current during welding can be stabilized and the strength can be increased. In addition, the arrangement relationship of the outer welded portion 38 and the inner welded portion 40 with respect to the bolt holes 34 and 36 is combined to effectively increase the strength of the entire outer member 14 when receiving an input in the axial direction X. Can do.

In order to confirm the welding strength of the outer member 14 according to the above embodiment, a tensile test was performed using an autograph manufactured by Shimadzu Corporation to measure the breaking strength. In the measurement, instead of the inner cylinder member 12 and the rubber-like elastic body 16, a disk having the same outer shape as the inner cylinder member 12 is arranged and the bolt holes 34 and 36 are fixed, and the second outer side is secured by the disk. A load was applied below the second wall portion 24A of the metal fitting 24 in the axial direction X, and the stress value of the welded portion was obtained from the breaking strength. For comparison, the welding arrangement configurations shown in FIGS. 7B to 7D were also measured in the same manner. FIG. 7A shows the welding arrangement configuration according to the above embodiment. The results are shown in Table 1.

  As shown in Table 1, when the welding arrangement configuration of the example, compared to the other configurations according to Comparative Examples 1 to 3, the strength of the welded portion is clearly higher, and an outer member having excellent strength is obtained. It was.

The top view of the vibration isolator which concerns on embodiment II-II sectional view of FIG. Sectional drawing which shows the state which assembled | attached the vibration isolator to the vehicle body The top view which shows the state which couple | bonded the 2nd outer metal fitting and the 3rd outer metal fitting of the vibration isolator VV line sectional view of FIG. Sectional view before joining the second outer metal fitting and the third outer metal fitting Schematic which shows the welding arrangement configuration of the outer member which concerns on an Example and a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Vibration isolator 12 ... Inner cylinder member 14 ... Outer member 16 ... Rubber-like elastic body, 16A ... Upper surface (Axial direction one surface)
22 ... 1st outer metal fitting, 22A ... 1st wall part, 22B ... cylindrical part, 22C ... 1st flange part 24 ... 2nd outer metal fitting, 24A ... 2nd wall part, 24B ... 2nd flange part 26 ... 3rd Outer bracket 34, 36 ... Bolt hole (bolt fastening part)
38 ... Outer welded portion 40 ... Inner welded portion 2A ... Mounted surface C ... Circumferential direction L ... Longer diagonal (straight line connecting two bolt fastening portions)
M: Shorter diagonal (straight line perpendicular to straight line L)
O ... Axial core X ... Axial direction Y ... Axis perpendicular direction, Y1 ... Outward, Y2 ... Inward

Claims (1)

An inner cylindrical member; an annular rubber-like elastic body provided on an outer peripheral portion of the inner cylindrical member; An anti-vibration device comprising an outer member coupled via a body,
The outer member is
A first outer metal fitting having a ring-plate-shaped first wall portion that is brought into contact with one axial surface of the rubber-like elastic body and having a first flange portion extending outward in a direction perpendicular to the axial direction over the entire circumference; ,
A second flange portion that has a ring plate-like second wall portion that clamps the rubber-like elastic body in the axial direction between the first wall portion and a second flange portion that is overlapped and fixed to the first flange portion; 2 outer brackets,
An annular third outer metal fitting fixed on the surface opposite to the first outer metal fitting with respect to the second wall portion of the second outer metal fitting,
Consists of
In the overlapping portion of the first flange portion and the second flange portion, bolt fastening portions with respect to the mounting surface are provided at two locations facing in the direction perpendicular to the axis across the axis of the inner cylinder member,
A first flange portion of the first outer metal fitting and a second flange portion of the second outer metal fitting are arranged at six points of outer welded portions that are evenly arranged in the circumferential direction on the inner side perpendicular to the axis of the bolt fastening portion. The two outer welds that are fixed in the direction perpendicular to the axis are arranged on a straight line orthogonal to a straight line connecting the two bolt fastening parts,
The second wall portion of the second outer metal fitting and the third outer metal fitting are fixed by three inner welded portions that are equally arranged in the circumferential direction on the inner peripheral side of the outer welded portion, and The inner welded portion is arranged on a straight line orthogonal to the straight line connecting the two bolt fastening portions,
Anti-vibration device.

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